A few years ago I was attending a day lecture of an expert panel of neurologists on headaches. A recent research paper was discussed on the interconnections of the neurology of the neck and the dura. This is a great article on the interconnections of the dura and the pericranial tissues. Basically we have nerve interconnections that span the sutures and skull that connect our peripheral nerves with the lining of the brain, the dura, and the trigeminal nerve.

"We conclude that a proportion of meningeal afferents innervates extracranial tissues like periosteum and pericranial muscles via collaterals projecting through the skull. These afferents may be nociceptive, some may subserve proprioceptive functions. The finding of extracranial projections of meningeal afferents may be important for our understanding of extracranial impacts on headache generation and therapy."

There were fibers that had a source with the mandibular and maxillary branches of the trigeminal ganglion as well as the spinal trigeminal tract. The trigeminal nucleus descends into the upper cervical spinal cord and interconnects with the upper neck. This helps us explain referred pain from the upper neck into the face. (The sensory innervation of the upper neck goes to the back of the skull.) It also explains the complex interconnections and coordination of the jaw, teeth and muscles of mastication and the upper neck.

"Results.—In addition to a network of meningeal nerve fibers, several fiber bundles were observed, leaving the skull through emissary canals and fissures to innervate the pericranial temporal, parietal, and occipital periosteum. Traced fibers were seen spreading into deep layers of the temporal and upper neck muscles. Retrograde neuronal tracing revealed labeled cell bodies exclusively in the mandibular and maxillary division of the rat trigeminal ganglion, and centrally projecting fibers were identified in the spinal trigeminal tract. Electron microscopy of the cross-sected spinosus nerve showed myelinated and unmyelinated axons with similar numbers in human and rat."

This could explain why cranial suture treatment as well as cranial nerves and upper cervical nerves, the Greater and Lesser Occipital nerves, are helpful in reducing or resolving facial pain and headaches.

Clinical Application

I learned a few things that day. One was that we as medical professional groups stick to our kind and read our own research. (Mostly) We also see these medical problems through our own professional lens. I tend to look at the cervical spine and a musculoskeletal answer for a patient’s pain. A neurologist looks at their toolbox and finds a drug that will work. A proctologist… well, you get the gist. Here are a few questions we can ask ourselves to get better at the practice of medicine.

What is the lens that you are using to look and assess the problems of the patient before you?

Who can you build a relationship with to ‘broaden your view’ of the problems of our patients?

Another thing I learned was that there was a connection that explained why addressing upper cervical structures could have a powerful effect on migraines.

“This pattern of innervation could, for example, explain the aggravating influences of neck muscle tension on tension‐type headache and migraine.”

The conclusion at the end of the round table was that these neurologists needed “better drugs”. The discussion at the end of the article suggested that this interconnection could explain why manual therapies, as well as Botox and injections, work in reducing or resolving tension type headaches and migraines. This was not the ‘take home’ from the panel but a medication option.

“and may explain why manual therapies of pericranial structures can be successful in the management of headaches. It may also partly be an explanation for the beneficial effects of local anesthetic or botulinum toxin injections into peripheral nerves, or the so‐called trigger points of pericranial tissues.”

When Botox or injections work we need to ask the question ‘why’. Why did these injections help? Why are the upper cervical muscles under load or tension?

A recent case that I had the privilege of working with had an MRI ordered of the cervical spine. Her pain was consistently at the C2 level, and the articulations above and below. She had no nerve findings of weakness or sensory changes. The radiology report did not include any description above the body of C2 and the focus was on the mid cervical spine. This area was not clinically painful to any testing. There was a finding that was relevant and signal changes were different form one side to the other. Can you spot the difference? Let Sesame Street help you. “One of these things is not like the other.” (Hint: check out the area of the alar ligaments.)

Left and Right Sagittal T2 MRI

I forgot to mention the nature of the injury of the patient example above. This was a severe whiplash injury and a failure to fully recover with signs of instability and poor neck control and poor tolerance to increased activity. There is fluid in the area of the right alar ligament on the T2 weighted sagittal view. This is consistent with fluid and is not present on the left side. The dens on the sagittal slice just medial showed some bony signal changes at the area of the main attachment point of the right alar ligament. The mid cervical spine had no signal changes indicative of swelling or active processes and appeared ‘stable’ suggesting chronic degenerative changes.

Will this information change how we look at this case? You bet! Sadly, the radiologist report does not include anything above the body of C2. The axial views stop at the mid body of C2. Currently mid cervical injections are planned. She has just started to see a chiropractor that is planning on manipulating the neck. Just writing this makes me cringe a little.

When Botox or neck injections help reduce headache pain ask ‘why’.

Here is a great article on upper cervical ligament injuries following whiplash injuries that have continued pain and dysfunction. It is part of a series of great articles and if you treat the neck I would recommend reading them.

Our patients want to know two things. What do they have? They also want to know what they can do for their problem. They are not looking for another medication. They want to understand and they want to be a part of their care and healing process.

Where can we as medical professionals engage in dialogue with other professions? Great question! BETTER is a platform that can help.